Installing 2m 70cm antenna on bumper pull camper

I am planning to install a mobile dual band radio in my Springdale bumper pull camper. I'm wanting an antenna with decent gain that I can permanently mount to the roof and fold down for travel, fold up when parked. I know I want it up on the roof and not down on the bumper. I know my roof is covered in white rubber, I have no idea what is under that rubber. The camper is only a few years old. I can seal the hole but I'm not sure about antenna model, ground plane or mount.



I usually do NMO mounts on the roof of my cars but I've never messed with folding mounts. What types of antennas do you like for this application? I don't have to stick to the typical 19" like I usually run in town. When I need more on my NMO mounts I usually switch to the Larsen NMO 2/70.



Any suggestions for folding mounts for the roof of a camper, possibly no ground plane, with some gain?

Installing 2m 70cm antenna on bumper pull camper